SCIENCE - Kelp can adapt to climate change

As the Earth experiences climate change, the environmental impact on marine plant life in arctic waters is of great concern. Currently, the European Arctic is experiencing strong ecological shifts due to rising sea temperatures. As the glaciers and snow melt, an excess of freshwater is being introduced into the seawater, which significantly changes the salinity of the ocean. The effects on Alaria esculenta, one of the key kelp species found in the high Arctic marine fjord ecosystems, can be a predictive marker for how other organisms will adapt to these changes.

Researchers from the University of Bremen, Alfred Wegener Institute, University of Innsbruck, and University of Salzburg published a study in Phycologiatesting the adaptive capability of A. esculenta. Because this type of kelp is primarily found closer to the surface, it is more susceptible to salinity, temperature, and UV changes from climate change. According to journal editor, Professor David Garbary, “this study provides real insight into how marine aquatic plants in the Arctic can adapt to multiple stresses from climate change, not only the obvious temperature increases affecting terrestrial communities.”

Samples of A. esculenta were collected from the Arctic waters of Spitsbergen, an island off the coast of Norway. After being transported back to a laboratory, the researchers exposed the kelp to low salinity water and increased UV radiation. This was done to determine its adaptability to dramatic ecological changes by viewing how the changes in one stress factor will affect the changes in another stress factor, termed cross-acclimation. The researchers tested the reactions to light sensitivity, biochemical structure of the seaweed, and basic cell structure as markers of adaptability.

The researchers found that the kelp was able to change its cellular structure to compensate for the decreased salinity and increased UV radiation. It was also observed that a redistribution of micronutrients within the cells helped protect against the UV light. Dr. Kai Bishof remarked that this change in characteristics could be viewed as, “A general stress response mechanism. In a highly dynamic environment, the application of such a general protective feature constitutes a fast and cost-efficient strategy for maintaining proper physiological functions.”

The idea of cross-acclimation has been studied in other plant life, but this is the first time it has been applied to kelp. The researchers found a direct correlation between lowering the salinity of the water and increasing the UV radiation. The kelp was able to adapt its cell structure to protect against the UV light. This finding shows that A. esculenta has the ability to continue to thrive, even with the dramatic environmental shifts of climate change.